Despite the proliferation of collapse explanations in the wake
of the attack, the reaction to the collapses at the time was
almost universally one of shock and amazement.
Certainly this new phenomenon -- the total
progressive collapse
of steel-framed buildings -- should have triggered the most painstaking
and fully resourced investigations.
The structural steel parts, whose failures were blamed for the collapses,
should have been documented on-site before being removed to warehouses
for further study.
That is the procedure used in archaeological digs
and in normal crime scene investigations.